Digg
A news aggregator started in 2004 by Kevin Rose. Users submitted links and voted — "digg" or "bury" — and whatever got the most votes hit the front page.
Around 2008 it was one of the most powerful sites on the web: reaching Digg's front page brought so much traffic that servers collapsed, a phenomenon that got its own name, "the Digg effect". Its fall is a product management classic. The v4 redesign (2010) removed user submission in favour of publisher content, weakened the community's influence and was perceived as a betrayal — users moved to Reddit essentially over one weekend, and Reddit never looked back. What was left of the company was sold off in pieces in 2012. The brand has been revived in recent years by its founder together with Reddit co-founder Alexis Ohanian.